We look at the division of 13085140 by 309 
Let's see how many times 309 fits into 13085140.

Going ahead to step 1:
When dividing 1 by 309, we get 0 with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 309

Going ahead to step 2:
309 goes into 13 0 times with a remainder of 13.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 13 leaves us with 13.
Take the next digit (0) from the dividend and append it to 13, then repeat: 130 / 309

Going ahead to step 3:
309 goes into 130 0 times with a remainder of 130.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 130 and we're left with 130.
Fetch the next digit (8) from the dividend, attach it to 130 and continue: 1308 / 309

Step 4:
309 can be fit into 1308 4 times, resulting in a remainder of 72.
Write down 4 as next digit of the result. 
Result so far: 4.0
Deduct 1236 from 1308 and we're left with 72.
Grab the next digit (5) from the dividend, add it to 72, then carry on: 725 / 309

Step 5:
725 divided by 309 is 2 with a remainder of 107.
Write down 2 as next digit of the result. 
Result so far: 42.0
Deduct 618 from 725 and we're left with 107.
Append the next digit (1) from the dividend to 107 and continue with: 1071 / 309

Step 6:
309 goes into 1071 3 times with a remainder of 144.
Record the quotient 3 as the next digit in the result. 
Result so far: 423.0
Deduct 927 from 1071 and we're left with 144.
Fetch the next digit (4) from the dividend, attach it to 144 and continue: 1444 / 309

On to step 7:
The number 309 fits into 1444 4 times, leaving a remainder of 208.
Write down 4 as next digit of the result. 
Result so far: 4234.0
The remainder is 208 after subtracting 1236 from 1444.
Include the next digit (0) from the dividend after 208, then repeat: 2080 / 309

Moving on to step 8:
309 goes into 2080 6 times with a remainder of 226.
Use 6 as the next digit of our solution. 
Result so far: 42346.0
If we take 1854 away from 2080, we end up with 226.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2260, and continue the process.

Moving on to step 9:
The number 309 fits into 2260 7 times, leaving a remainder of 97.
Record the quotient 7 as the next digit in the result. 
Result so far: 42346.7
Subtract 2163 from 2260 to get 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Going ahead to step 10:
The number 309 fits into 970 3 times, leaving a remainder of 43.
The number 3 becomes the next digit in our result. 
Result so far: 42346.73
If we take 927 away from 970, we end up with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

On to step 11:
309 goes into 430 1 times with a remainder of 121.
The number 1 becomes the next digit in our result. 
Result so far: 42346.731
The remainder is 121 after subtracting 309 from 430.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1210, and continue the process.

Advancing to step 12:
When dividing 1210 by 309, we get 3 with a remainder of 283.
Use 3 as the next digit of our solution. 
Result so far: 42346.7313
If we take 927 away from 1210, we end up with 283.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2830, and continue the process.

Moving on to step 13:
When dividing 2830 by 309, we get 9 with a remainder of 49.
Record the quotient 9 as the next digit in the result. 
Result so far: 42346.73139
If we take 2781 away from 2830, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

On to step 14:
490 divided by 309 is 1 with a remainder of 181.
Write down 1 as next digit of the result. 
Result so far: 42346.731391
Subtract 309 from 490 to get 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

Going ahead to step 15:
1810 divided by 309 is 5 with a remainder of 265.
The number 5 becomes the next digit in our result. 
Result so far: 42346.7313915
Subtracting 1545 from 1810 leaves us with 265.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2650, and continue the process.

Moving on to step 16:
When dividing 2650 by 309, we get 8 with a remainder of 178.
Put 8 as the next digit of the answer. 
Result so far: 42346.73139158
The remainder is 178 after subtracting 2472 from 2650.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1780, and continue the process.

In conclusion, the division gives 42346.73139158 with a balance of 1.78e-07.